And in that moment, I swear we were infinite! ...Or at least, we will be, later, when we scoot into our local theater today and see "The Perks of Being a Wallflower" on the big screen at last. But before we go to the movies, we've got to get through our rundown of all the characters who surround Charlie the wily wallflower in his fictional world. And in the spotlight this time: his sister, a complex character who remains nameless in the book but got hooked up with a name (Candace) for cinematic purposes.

Who she is: Charlie's sister starts out as a cipher whose feelings toward her brother range from indifferent annoyance to flat-out hostility. Candace has all the hallmarks of a high school success story—she's smart, engaged and high-achieving—but inside her is a core of self-loathing so powerful and poisonous that she believes she's at her best when she's being treated badly. (You know Charlie's quote from the trailer about how "We accept the love that we think we deserve"? Nobody proves it better than his sister.)

Who's playing her: Nina Dobrev, best known as the smoldering star of "The Vampire Diaries," who took a break from supernatural small-screen showbiz to test her skills in a more realistic role. (Fun fact: Nina was so devoted to landing the part that when it turned out she couldn't make room in her schedule for an in-person audition, she faked a bathroom break during another production in order to try for the part via Skype!)

Nina on Candace: "I'm playing a different character than I've played before," Nina told MTV News when we visited her on the "Perks" set. "She's more frigid, and she's a schoolgirl, and she's got straight As, and she wants to be perfect, and she's the president of like 50 clubs." And if her role, and this film, seems like a departure from Nina's past projects... well, you're right: "Every hiatus [from "Vampire Diaries"], my goal is to try something different, and this is a small part in a great fun indie that has a great script," she said. "I'm really proud to be part of it."

"The Perks of Being a Wallflower" opens today in New York and L.A. theaters, expanding to other select theaters on September 28.